Marathon runner Mina Guli will mark the beginning of her greatest running challenge on Sunday while campaigning for water conservation.

Guli, who is from Australia, will take on 100 marathons in 100 consecutive days, starting with the NYC Marathon.

“People look at me like I’m crazy, and maybe I am,” said Guli, “but it’s all for a good cause."

Water scarcity came to Guli's attention when she learned about the amount of water used to create just a single article of clothing.

"Water is the thing that gives us life. It brings us power in the economy, community, it helps turn lights on, computers, it’s in our daily consumptions, and even the clothes we’re wearing," Guli said. "I knew I needed to do something about it and created a foundation to educate the next generation of consumers."

She serves as CEO of Thirst for Water, a call to people worldwide to join together to change the way we all use, consume and think about water. According to the foundation, more than 95 percent of the water we use every day is inside the things we wear, eat and consume, leaving little for plant, animal and human consumption.

But Guli knew a foundation alone wouldn't be enough to raise awareness. She felt she needed to "do something crazy" in order to inform people around the world.

"I chose to run 100 marathons in 100 days because I want to show my 100 percent dedication to the cause."

Guli, a lawyer, says she "was never a sporty kid." Despite her "lifelong antipathy towards sport," a prank push into a pool left her with a back injury that she worked to overcome with the help of swimming. The pool led her to try running, as she "pushed to prove" to herself that she could "defy odds."

On Sunday, Guli won't just be running. She looks to speak with individuals about water problems and solutions.

"Running (in each of the cities) allows me to get out there and experience the realities of the water crisis; to speak to people, to walk beside them and see with my own eyes what's really happening on the ground," she said.

Guli chose one of the most iconic cities in the world to be her starting and end point of the marathons — New York City.

"It’s easy to forget that the world is running dry when you live in a place like New York, but water is everywhere," said Guli, who will be running her first NYC marathon. "I think for me being here is an opportunity to illustrate the problems that are global.”

After New York, she will run through Europe, Asia, Africa, Australia and South America before heading back to the United States to finish her campaign in New York on Feb. 11.

Guli has never taken on a physical challenge quite like this, but she's had a lot of practice. In 2017, she completed 40 marathons in 40 days along six rivers around the world. She's also participated in 40 marathons across seven deserts on seven continents in seven weeks.

Unsure of how her body will react to the everyday grind, she's been preparing by going to the gym, running and eating healthily. However, she says it's the "mental and emotional elements,"she knows will keep her going.

"It's the people I meet along the way, when speaking to them," Guli said. "It's looking at the faces of the people, and knowing they believe in me, telling me they know I can do this."

Guli said even small sacrifices make a difference in water conservation.

"I teamed up with Colgate, who is as much dedicated to saving water as I am," said Guli. "And our goal is for people to see little things such as turning the faucet off while brushing their teeth saves a massive amount of water."

Guli admits she's feeling a tad intimidated and overwhelmed before her journey across six continents even begins, but knows it will be worth it.

"I want to see changes for the next generations to come," she said. "And I know it starts with us now."